Sander attachment for a drill

ABSTRACT

The present invention is a sanding bit for use with an electric drill. The bit consists of an elongated member having a drill shaft formed on a first end of the member and a slot formed on a second end of the member. The slot is dimensioned and configured to receive an elongated strip of flexible sandpaper. The sandpaper strip is wound around the second end of the member to form a plurality of layers around the second end of the member. A barrel portion is formed on the second end of the member, the barrel portion having a greater cross-sectional diameter than the shaft. The slot may bifurcate the barrel member. The barrel portion may be cylindrical or conical.

FIELD OF THE INVENTION

The invention relates generally to drill attachments for use in sanding.

BACKGROUND OF THE INVENTION

There are numerous attachments and bits for use with electric drills. Inaddition to drill bits, electric drills can be used with grinding,cutting and sanding attachments. Drill bits which are designed for useas sanders are well known in the market. These sanding attachmentsgenerally come in two different forms. The first form consists of acircular pad mounted to a drill shaft. The drill shaft is inserted intothe chuck of the drill and a circular piece of sandpaper is attached tothe circular pad. The sandpaper is usually attached to the pad by meansof either an adhesive or by means of a recessed flanged bolt at thecenter of the pad. When the drill is activated, the circular pad spinsallowing the user to sand down an item by applying the sandpaper coveredpad to the item. After extensive use, the grit on the sandpaper willeither wear away or become clogged and will have to be replaced. Thistype of sanding device is very popular; however, it can only be used onlarge flat surfaces because of the size of the circular pad.

Another common sander attachment for drills consists of a cylindricalabrasive stone coaxially attached to a drill shaft. The drill shaft isattached to the chuck of the drill before use. When the drill isactivated, the cylindrical abrasive stone spins about its axis and canbe used to sand or grind. This type of sanding attachment is alsopopular and is suitable for use in tight corners. The abrasive stonescome in a variety of different grits, thereby allowing the user tochange from one abrasive stone to another as required. Once the grit onthe surface of the stone wears off, the stone must be replaced.Unfortunately, these stones have a relatively small surface area, whichin turn means that they wear out relatively quickly. An improved sandingattachment which is more durable and less expensive than a traditionalcylindrical grinding stone would be more extensively used in the market.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a sandingbit for use with an electric drill. The bit consists of an elongatedmember having a drill shaft formed on a first end of the member and aslot formed on a second end of the member. The slot is dimensioned andconfigured to receive an elongated strip of flexible sandpaper. Thesandpaper strip is wound around the second end of the member to form aplurality of layers around the second end of the member.

With the foregoing in view, and other advantages as will become apparentto those skilled in the art to which this invention relates as thisspecification proceeds, the invention is herein described by referenceto the accompanying drawings forming a part hereof, which includes adescription of the preferred typical embodiment of the principles of thepresent invention.

DESCRIPTION OF THE DRAWINGS

FIG. 1. is a perspective view of a sander attachment made in accordancewith the invention.

FIG. 2. is a top view of a strip of sandpaper for use with theinvention.

FIG. 3. is a side view of the sander attachment shown in FIG. 1 incombination with an electric drill.

FIG. 4. is an end view of the sander attachment made in accordance withthe invention.

FIG. 5. is an end view of the sander attachment with a strip ofsandpaper being attached thereto.

FIG. 6. is an end view of the sander attachment with a strip ofsandpaper wound about the attachment.

FIG. 7 a. is a perspective view of the preferred embodiment of thepresent invention.

FIG. 7 b. is a perspective view of another embodiment of the presentinvention.

FIG. 7 c. is a perspective view of another embodiment of the presentinvention.

In the drawings like characters of reference indicate correspondingparts in the different figures.

DETAILED DESCRIPTION OF THE INVENTION

Referring firstly to FIGS. 1, 2 and 3, the sander attachment, showngenerally as item 10 consists of a barrel member 12 coaxially mounted toa drill shaft 14. Shaft 14 is dimensioned and configured to releasablymount to chuck 16 of electric drill 18. Barrel 12 has slot 20 whichbifurcates the barrel. Slot 20 is dimensioned and configured to receiveelongated sandpaper strip 22. Sandpaper strip 22 is preferablyrectangular and has ends 24 and 26 and has abrasive surface 28.Sandpaper strip 22 is suitably flexible to permit it to be wound aroundbarrel 12. Slot 20 is dimensioned and configured to snugly receive end24 of sandpaper strip 22. Sandpaper strip 22 is wound around barrel 12with abrasive side 28 oriented away from the barrel member. Barrelmember 12 and drill shaft 14 are preferably made from a strong materialsuch as steel or brass. Preferably, drill bit 10 may be made from asingle piece of metal such that barrel 12 and shaft 14 are contiguous.

Referring now to FIGS. 4, 5 and 6, sandpaper strip 22 is wound aroundbarrel 12 in a spiral as illustrated in FIGS. 5 and 6. End 24 is firstinserted into slot 20 of barrel 12 and then strip 22 is wound around thebarrel in a spiral with abrasive surface 28 oriented on the outside ofthe spiral. Preferably, strip 22 is tightly wound around the barrel toform at least three layers of sandpaper, namely layers 30, 32 and 34. Ofcourse, the number of layers will be determined by the diameter ofbarrel 12 and the length of strip 22. When the sandpaper is fully woundonto the barrel, the finished bit can be attached to the drill's chuck(see FIG. 3). In operation, the bit should be rotated in the directionindicated by arrow 36 in order to ensure that the sandpaper remainstightly wound onto the barrel. Since the slot bifurcates barrel 12, thesandpaper strip can be positioned such that portion 25 of end 24 extendsbeyond the slot. The rest of the strip may be wound over portion 25 toensure that the sandpaper is securely retained onto the barrel.

The present invention has several advantages over the prior art.Firstly, since the barrel portion acts as a holder for sandpaper anddoes not have any abrasive characteristics itself, the drill bit can beused for a variety of different sanding and grinding applications simplyby changing the type of sandpaper wrapped around the barrel. Hence,where the sander is to be used to remove a large amount of material, arelatively coarse grade of sandpaper can be used. Where the applicationcalls for finer work, a fine grained sandpaper or emery cloth may beused. Also, since the bit may be made from a single piece of ordinarysteel or brass, the bit may be made very inexpensively. Mostsignificantly, since the sandpaper forms a plurality of layers aroundthe barrel, the bit can be used for an extended period of time beforehaving to change the sandpaper.

As the bit is used, the outermost sandpaper layer is slowly worn away,exposing a fresh layer of sandpaper beneath. In the event that a verydurable sandpaper is used, the outermost layers can simply be removed asthey become worn down or clogged up. As the worn layers are removed, theunderlaying fresh layer is exposed, permitting the sanding bit to beused for a longer period of time. When the last layer of sandpaper isworn away, a new strip can be easily added.

An alternate embodiment of the present invention is shown in FIG. 7 b.Bit 40 consists of a conical barrel portion 42 coaxially mounted to adrill shaft 44. Barrel portion 42 has first end 49 and second end 48.Slot 46 bifurcates end 48. Barrel portion 42 tapers away from shaft 44such that the cross-sectional diameter of end 48 is less than thecross-sectional diameter of end 49. As with the previous embodiment, anelongated strip of sandpaper is inserted into slot 46 and then woundaround the barrel in a spiral fashion. Since barrel 42 is conical, thesandpaper may be wrapped around the barrel to form a flared horn asindicated in FIG. 8. This flared horn structure is relatively flexible,allowing to the user to apply more uniform and gentle pressure onto thesurface of the item being worked with (not shown).

Another alternate embodiment of the present invention is shown in FIG. 7c. Bit 50 consists of a conical barrel portion 52 coaxially mounted todrill shaft 54. Barrel portion 52 has first end 59 and second end 58.Slot 56 bifurcates end 58. Barrel portion 52 tapers towards shaft 54such that the cross-sectional diameter of end 58 is greater than thecross-sectional diameter of end 59. As with the previous embodiments, anelongated strip of sandpaper is inserted into slot 56 and then woundaround the barrel in a spiral fashion. As in the previous embodiment,since barrel 52 is conical, the sandpaper may be wrapped around thebarrel to form a flared horn as indicated in FIG. 9. This flared hornstructure is relatively flexible, allowing to the user to apply moreuniform and gentle pressure onto the surface of the item being workedwith (not shown). The flared horn structure as shown in FIGS. 8 and 9are suitable for sanding uneven surfaces.

A specific embodiment of the present invention has been disclosed;however, several variations of the disclosed embodiment could beenvisioned as within the scope of this invention. It is to be understoodthat the present invention is not limited to the embodiments describedabove, but encompasses any and all embodiments within the scope of thefollowing claims.

1. A sanding bit for use with an electric drill, said bit comprising: a)a barrel body having opposite first and second ends and a longitudinalaxis, b) an elongated drill shaft coaxially mounted to the first end ofthe barrel body, c) the barrel body having a slot passing through thesecond end of the barrel body, d) a strip of sandpaper threaded throughthe slot and wound around the barrel body.
 2. The sanding bit of claim 1wherein the strip of sandpaper has an abrasive surface and wherein thesandpaper is wound around the body such that the abrasive surface of thesand paper is oriented away from the barrel body.
 3. The sanding bit ofclaim 1 wherein the slot is dimensioned to snugly receive the strip ofsandpaper.
 4. The sanding bit of claim 2 wherein the sandpaper is woundaround the barrel body in a spiral to form a plurality of sandpaperlayers around the cylindrical member.
 5. The sanding bit of claim 1wherein the barrel body is cylindrical.
 6. The sanding bit of claim 5wherein the sandpaper has an abrasive surface and wherein the sandpaperis wound around the barrel body in a spiral to form a plurality oflayers with the abrasive surface of the sand paper oriented away fromthe barrel body.
 7. The sanding bit of claim 1 wherein the barrel bodyis conical and wherein the second end of the barrel body is broader thanthe first end of the barrel body.
 8. The sanding bit of claim 7 whereinthe sandpaper has an abrasive surface and wherein the sandpaper is woundaround the barrel body in a spiral to form a plurality of layers withthe abrasive surface of the sand paper oriented away from the barrelbody.
 9. The sanding bit of claim 1 wherein the barrel body is conicaland wherein the first end of the barrel body is broader than the secondend of the barrel body.
 10. The sanding bit of claim 9 wherein thesandpaper has an abrasive surface and wherein the sandpaper is woundaround the barrel body in a spiral to form a plurality of layers withthe abrasive surface of the sand paper oriented away from the barrelbody.
 11. A sanding bit for use with an electric drill, said bitcomprising an elongated member having a drill shaft formed on a firstend of the member and a slot formed on a second end of the member, slotdimensioned and configured to receive an elongated strip of flexiblesandpaper, the sandpaper strip being wound around the second end of themember to form a plurality of layers around the second end of themember.
 12. The sanding bit of claim 11 wherein the slot bifurcates thesecond end of the member.
 13. The sanding bit of claim 11 wherein thesecond end forms a barrel member, the barrel member and the drill shafthaving cross-sectional diameters, the diameter of the barrel memberbeing greater than that of the shaft.
 14. The sanding bit of claim 13wherein the barrel member is cylindrical.
 15. The sanding bit of claim13 wherein the barrel member is conical and wherein the conical barrelmember tapers away from the drill shaft.
 16. The sanding bit of claim 13wherein the barrel member is conical and wherein the conical barrelmember tapers towards the drill shaft.